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Abstract:

A battery module and methods for bonding a cell terminal of a battery to
an interconnect member are provided. The battery module includes a
battery cell having a cell terminal, and an exothermal reactive layer
having first and second sides. The first side is disposed adjacent to the
cell terminal. The module further includes an interconnect member
disposed adjacent to the second side of the exothermal reactive layer.
The exothermal reactive layer is ignited to form a bonding joint between
the interconnect member and the cell terminal in response to a laser beam
contacting at least a portion of the exothermal reactive layer.

Claims:

1. A battery module, comprising: a battery cell having a cell terminal;
an exothermal reactive layer having first and second sides, the first
side being disposed adjacent to the cell terminal; and an interconnect
member disposed adjacent to the second side of the exothermal reactive
layer, the exothermal reactive layer is configured to ignite to form a
bonding joint between the interconnect member and the cell terminal in
response to a laser beam contacting at least a portion of the exothermal
reactive layer.

2. The battery module of claim 1, wherein the exothermal reactive layer
comprises a plurality of aluminum layers and a plurality of nickel
layers.

3. The battery module of claim 1, wherein the first side of the
exothermal reactive cell is an aluminum layer of the plurality of
aluminum layers, and the cell terminal is an aluminum cell terminal.

4. The battery module of claim 3, wherein the second side of the
exothermal reactive layer is a nickel layer of the plurality of nickel
layers, and the interconnect member is a nickel-plated copper
interconnect member.

5. The battery module of claim 1, wherein the first side of the
exothermal reactive layer is a nickel layer of the plurality of nickel
layers, and the cell terminal is nickel-plated copper cell terminal.

6. The battery module of claim 5, wherein the second side of the
exothermal reactive layer is another nickel layer of the plurality of
nickel layers, and the interconnect member is a nickel-plated copper
interconnect member.

7. The battery module of claim 1, wherein a thickness of the exothermal
reactive layer is 40-200 microns.

8. A method for bonding a cell terminal of a battery to an interconnect
member, comprising: disposing an exothermal reactive layer between the
interconnect member and the cell terminal of the battery cell, utilizing
a component placement machine; and emitting a laser beam from a laser for
a predetermined amount of time that contacts at least a portion of the
exothermal reactive layer and ignites the exothermal reactive layer to
form a bonding joint between the interconnect member and the cell
terminal.

9. The method of claim 8, wherein the laser beam has a power density of
0.1.times.10.sup.8 Watts/cm2 to 5.0.times.10.sup.8 Watts/cm2 at
the portion of the exothermal reactive layer.

10. The method of claim 8, wherein the exothermal reactive layer
comprises a plurality of aluminum layers and a plurality of nickel
layers.

11. The method of claim 8, wherein a thickness of the exothermal reactive
layer is 40-200 microns.

12. A method for bonding a cell terminal of a battery to an interconnect
member, comprising: disposing the interconnect member having an
exothermal reactive layer previously disposed thereon adjacent to the
cell terminal utilizing a component placement machine; emitting a laser
beam from a laser for a predetermined amount of time that contacts at
least a portion of the exothermal reactive layer and ignites the
exothermal reactive layer to form a bonding joint between the
interconnect member and the cell terminal.

13. The method of claim 12, wherein the laser beam has a power density of
0.1.times.10.sup.8 Watts/cm2 to 5.0.times.10.sup.8 Watts/cm2 at
the portion of the exothermal reactive layer.

14. The method of claim 12, wherein the exothermal reactive layer
comprises a plurality of aluminum layers and a plurality of nickel
layers.

15. The method of claim 12, wherein a thickness of the exothermal
reactive layer is 40-200 microns.

16. The method of claim 12, wherein the predetermined amount of time is
less than 0.1 milliseconds.

17. A method for bonding a cell terminal of a battery to an interconnect
member, comprising: disposing the cell terminal having an exothermal
reactive layer previously disposed thereon adjacent to the interconnect
layer utilizing a component placement machine; and emitting a laser beam
from a laser for a predetermined amount of time that contacts at least a
portion of the exothermal reactive layer and ignites the exothermal
reactive layer to form a bonding joint between the interconnect member
and the cell terminal.

18. The method of claim 17, wherein the laser beam has at least 10.sup.8
Watts/cm2 at the portion of the exothermal reactive layer.

19. The method of claim 17, wherein the exothermal reactive layer
comprises a plurality of aluminum layers and a plurality of nickel
layers.

20. The method of claim 17, wherein a thickness of the exothermal
reactive layer is 40-200 microns.

Description:

BACKGROUND

[0001] Battery modules have battery cells with cell terminals that are
welded to interconnect devices. However, ultrasonic welding devices have
a relatively long cycle time for welding cell terminals to interconnect
devices. Further, a welding tool of an ultrasonic welding device must be
sequentially moved to each cell of a plurality of cell terminals that
takes a relatively large amount of manufacturing time. Further, the
welding tool must be allowed to cool between each weld that takes an
additional amount of manufacturing time.

[0002] Accordingly, the inventors herein have recognized a need for an
improved battery module and methods for bonding a cell terminal of a
battery module to an interconnect device.

SUMMARY

[0003] A battery module in accordance with an exemplary embodiment is
provided. The battery module includes a battery cell having a cell
terminal. The battery module further includes an exothermal reactive
layer having first and second sides. The first side is disposed adjacent
to the cell terminal The battery module further includes an interconnect
member disposed adjacent to the second side of the exothermal reactive
layer. The exothermal reactive layer is configured to ignite to form a
bonding joint between the interconnect member and the cell terminal in
response to a laser beam contacting at least a portion of the exothermal
reactive layer.

[0004] A method for bonding a cell terminal of a battery to an
interconnect member in accordance with another exemplary embodiment is
provided. The method includes disposing an exothermal reactive layer
between the interconnect member and the cell terminal of the battery
cell, utilizing a component placement machine. The method further
includes emitting a laser beam from a laser for a predetermined amount of
time that contacts at least a portion of the exothermal reactive layer
and ignites the exothermal reactive layer to form a bonding joint between
the interconnect member and the cell terminal.

[0005] A method for bonding a cell terminal of a battery to an
interconnect member in accordance with another exemplary embodiment is
provided. The method includes disposing the interconnect member having an
exothermal reactive layer previously disposed thereon adjacent to the
cell terminal utilizing a component placement machine. The method further
includes emitting a laser beam from a laser for a predetermined amount of
time that contacts at least a portion of the exothermal reactive layer
and ignites the exothermal reactive layer to form a bonding joint between
the interconnect member and the cell terminal.

[0006] A method for bonding a cell terminal of a battery to an
interconnect member in accordance with another exemplary embodiment is
provided. The method includes disposing the cell terminal having an
exothermal reactive layer previously disposed thereon adjacent to the
interconnect layer utilizing a component placement machine. The method
further includes emitting a laser beam from a laser for a predetermined
amount of time that contacts at least a portion of the exothermal
reactive layer and ignites the exothermal reactive layer to form a
bonding joint between the interconnect member and the cell terminal.

[0007] These and other advantages and features will become more apparent
from the following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a schematic of a battery module in accordance with an
exemplary embodiment;

[0009] FIG. 2 is a cross-sectional schematic of a top portion of the
battery module of FIG. 1;

[0010]FIG. 3 is a schematic of four battery cells and an interconnect
member utilized in the battery module of FIG. 1;

[0011]FIG. 4 is a cross-sectional schematic of the four battery cells and
the interconnect member of FIG. 3;

[0012] FIG. 5 is a simplified enlarged cross-sectional schematic of a
portion of an interconnect member, an exothermal reactive layer, and a
cell terminal in accordance with another exemplary embodiment;

[0013] FIG. 6 is a simplified enlarged cross-sectional schematic of a
portion of the exothermal reactive layer of FIG. 5;

[0014]FIG. 7 is a simplified enlarged cross-sectional schematic of a
portion of an interconnect member, an exothermal reactive layer, and a
cell terminal in accordance with another exemplary embodiment;

[0015]FIG. 8 is a simplified enlarged cross-sectional schematic of a
portion of the exothermal reactive layer of FIG. 7;

[0016]FIG. 9 is a block diagram of a system utilized to ignite an
exothermal reactive layer disposed between a cell terminal and an
interconnect member;

[0017] FIG. 10 is a flowchart of a method for bonding a cell terminal of
the battery to an interconnect member in accordance with another
exemplary embodiment;

[0018] FIG. 11 is a flowchart of another method for bonding a cell
terminal of the battery to an interconnect member in accordance with
another exemplary embodiment;

[0019] FIG. 12 is a flowchart of another method for bonding a cell
terminal of the battery to an interconnect member in accordance with
another exemplary embodiment;

[0020]FIG. 13 is a simplified enlarged cross-sectional schematic of a
portion of an interconnect member, a bonding joint, and a cell terminal
wherein the bonding joint is formed by igniting the exothermal reactive
layer of FIGS. 5; and

[0021] FIG. 14 is a simplified enlarged cross-sectional view of a portion
of an interconnect member, a bonding joint, and a cell terminal wherein
the bonding joint is formed by igniting the exothermal reactive layer of
FIG. 7.

DETAILED DESCRIPTION

[0022] Referring to the FIG. 1, a schematic of a battery module 10 that is
configured to provide electrical power to an battery-electric vehicle or
a hybrid vehicle in accordance with an exemplary embodiment is
illustrated. Referring to FIGS. 1, 2, and 4, the battery module 10
includes battery cells 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42,
44, 46, 47, 48, 50, frame members 60, 62, 64, 66, 68, 70, 72, 74, 76, a
circuit board 80, interconnect members 90, 92, 94, 96, 97, 98, 100, 102,
103 and exothermal reactive layers including exothermal reactive layers
110, 112. An advantage of the battery module 10 is that the module 10
utilizes exothermal reactive layers that can be ignited utilizing a laser
beam during manufacture of the module 10 to bond cell terminals of the
battery cells to associated interconnect members extremely quickly. An
exothermal reactive layer refers to a layer which generates heat after
being ignited.

[0023] Referring to FIGS. 2, 3 and 4, in the illustrated exemplary
embodiment, the battery cells 20-50 are lithium-ion battery cells.
Further, the structure of the battery cells 20-50 are substantially
similar to one another. Of course, in alternative embodiments, the
battery cells could be other types of battery cells known to those
skilled in the art.

[0024] The battery cell 20 includes a body portion 130, an extension
portion 132 extending around a periphery of the body portion 130, and
cell terminals 134, 135 extending outwardly from the extension portion
132. In one exemplary embodiment, the cell terminal 134 is a
nickel-plated copper cell terminal and the cell terminal 135 is an
aluminum cell terminal.

[0025] Further, the battery cell 22 includes a body portion 140, an
extension portion 142 extending around a periphery of the body portion
140, and cell terminals 144, 145 extending outwardly from the extension
portion 142. In one exemplary embodiment, the cell terminal 144 is a
nickel-plated copper cell terminal and the cell terminal 145 is an
aluminum cell terminal.

[0026] Also, the battery cell 24 includes a body portion 150, an extension
portion 152 extending around a periphery of the body portion 150, and
cell terminals 154, 155 extending outwardly from the extension portion
152. In one exemplary embodiment, the cell terminal 154 is a
nickel-plated copper cell terminal and the cell terminal 155 is an
aluminum cell terminal.

[0027] Further, the battery cell 26 includes a body portion 160, an
extension portion 162 extending around a periphery of the body portion
160, and cell terminals 164, 165 extending outwardly from the extension
portion 162. In one exemplary embodiment, the cell terminal 164 is a
nickel-plated copper cell terminal and the cell terminal 165 is an
aluminum cell terminal.

[0028] The frame members 60, 62, 64, 66, 68, 70, 72, 74, 76 are configured
to be coupled together to enclose the battery cells 20-50 therebetween,
and the frame members 60, 62 are configured to be coupled together and to
hold the battery cells 20, 22 therebetween. Further, the frame members
62, 64 are configured to be coupled together and to hold the battery
cells 24, 26 therebetween, and the frame members 64, 66 are configured to
be coupled together and to hold battery cells 28, 30 therebetween. Also,
the frame members 66, 68 are configured to be coupled together and to
hold battery cells 32, 34 therebetween, and the frame members 68, 70 are
configured to be coupled together and to hold battery cells 36, 38
therebetween. In addition, the frame members 70, 72 are configured to be
coupled together and to hold battery cells 40, 42 therebetween, and the
frame members 72, 74 are configured to be coupled together and to hold
battery cells 44, 46 therebetween. Finally, the frame members 74, 76 are
configured to be coupled together and to hold battery cells 48, 50
therebetween.

[0029] Referring to FIGS. 2, 4 and 5, the interconnect members 90, 92, 94,
96, 97, 98, 100, 102, 103 are provided to electrically couple cell
terminals of the battery cells 20-50 in series with one another. Since
the interconnect members 90, 92, 94, 96, 98, 100, 102 have a
substantially similar configuration, only the structure of interconnect
member 90 will be discussed in detail. The interconnect member 90 is
substantially U-shaped and has outer nickel layers 180, 184 and a central
copper layer 182. As illustrated, a surface of the nickel layer 184 is
disposed adjacent to a first side of the exothermal reactive layer 112
also having a nickel layer. In an alternative embodiment, the surface of
the nickel layer 184 is disposed adjacent to a first side of the
exothermal reactive layer 112 having an aluminum layer. In one exemplary
embodiment, a wall of the interconnect member 90 has a thickness in a
range of 0.5-1.0 millimeters. As shown in FIG. 2, the interconnect
members 97 and 103 have a different shape than the other interconnect
members, and the interconnect members 97 and 103 are constructed of the
same materials as the other interconnect members.

[0030] Referring to FIGS. 5, 6, and 13, the exothermal reactive layer 112
is provided to ignite in response to a laser beam contacting the
exothermal reactive layer 112 in order to form a bonding joint 700
between the interconnect member 90 and the cell terminal 154. In the
illustrated embodiment, the exothermal reactive layer 112 is constructed
of a plurality of nickel layers 200 and a plurality of aluminum layers
202. Each nickel layer 200 has an adjacent aluminum layer 202 disposed
thereon. The layers 200 and 202 are extremely thin and are deposited on
each other utilizing a vapor deposition process or a magnetron sputtering
process for example. Further, a total thickness of the exothermal
reactive layer 112 is in a range of 40-200 microns. The exothermal
reactive layer 112 has a first side disposed adjacent to a wall of the
interconnect member 90 and a second side disposed adjacent to the cell
terminal 154. Also, in one exemplary embodiment, the exothermal reactive
layer 112 comprises a product named "NanoFoil" manufactured by Indium
Corporation of America and is a separate component. In another
alternative embodiment, the layer 112 is formed on a portion of the outer
wall of the interconnect member 90 during manufacture of the interconnect
member 90. In still another alternative embodiment, the layer 112 is
formed on a portion of the cell terminal 154 during manufacture of the
battery cell 24.

[0031] Referring to FIGS. 2 and 5, in the illustrated embodiment, the
battery cells 20-50 have cell terminals with substantially similar
structures. Only the cell terminal 154 of the battery cell 24 will be
described in further detail. The cell terminal 154 has outer nickel
layers 220, 224 and a central copper layer 222 disposed between the
layers 220, 224. The nickel layer 220 is bonded (e.g., welded) to the
exothermal reactive layer 112. In an alternative embodiment, a thin
tin-alloy layer may be disposed between the cell terminal 154 and the
exothermal reactive layer 112 to assist in bonding the cell terminal 154
to the interconnect layer 90. Further, a thin tin-alloy layer may be
disposed between the interconnect member 90 and the exothermal reactive
layer 112 to assist in bonding the cell terminal 154 to the interconnect
layer 90. In the illustrated embodiment, a thickness of the cell terminal
154 is 0.2 millimeters. Of course, in alternative embodiments, a
thickness of the cell terminal 154 could be 0.1-0.2 millimeters for
example.

[0032] The exothermal reactive layer 112 is configured to ignite in
response a laser beam contacting the layer 112 with a power density of
0.1×108 Watts/cm2 to 5.0×108 Watts/cm2.
When ignited, the exothermal reactive layer 112 may burn at a temperature
level of at least 1200 degrees Celsius to form a bonding joint (e.g., a
weld joint) between the interconnect member 90 and the cell terminal 154.

[0033] Referring to FIG. 7, an alternative configuration for the
interconnect member, the exothermal reactive layer, and a cell terminal
will be discussed. In particular, an interconnect member 290, an
exothermal reactive layer 312, and a cell terminal 354 will be discussed.
The interconnect member 290 is substantially U-shaped and has outer
nickel layers 380, 384 and a central copper layer 382. As illustrated, a
surface of the nickel layer 384 is disposed adjacent to a first side of
the exothermal reactive layer 312. In one exemplary embodiment, a wall of
the interconnect member 290 has a thickness in a range of 0.5-1.0
millimeters.

[0034] Referring to FIGS. 7, 8 and 14, the exothermal reactive layer 312
is provided to ignite in response to a laser beam contacting the
exothermal reactive layer 312 in order to form a bonding joint 710
between the interconnect member 290 and the cell terminal 354. In the
illustrated embodiment, the exothermal reactive layer 312 is constructed
of a plurality of nickel layers 400 and a plurality of aluminum layers
402. Each nickel layer 400 has an adjacent aluminum layer 402 disposed of
thereon. The layers 400 and 402 are extremely thin and are deposited on
each other utilizing a vapor deposition process or a magnetron sputtering
process. Further, a thickness of the exothermal reactive layer 312 is in
a range of 40-200 microns. The exothermal reactive layer 312 has a first
side disposed adjacent to a wall of the interconnect member 290 and a
second side disposed adjacent to the cell terminal 354. Also, in one
exemplary embodiment, the exothermal reactive layer 412 comprises a
product named "NanoFoil" manufactured by Indium Corporation of America
and is a separate component. In another alternative embodiment, the layer
312 is formed on a portion of the outer wall of the interconnect member
290 during manufacture of the interconnect member 290. In still another
alternative embodiment, the layer 312 is formed on a portion of the cell
terminal 354 during manufacture of an associated battery cell.

[0035] The cell terminal 354 is constructed of aluminum and is bonded with
an aluminum layer of the exothermal reactive layer 312. In the
illustrated embodiment, a thickness of the cell terminal 354 is 0.2
millimeters. Of course, in an alternative embodiment, a thickness of the
cell terminal 354 is 0.1-0.2 millimeters.

[0036] The exothermal reactive layer 312 is configured to ignite in
response a laser beam contacting the layer 312 with a power density of
0.1×108 Watts/cm2 to 5.0×108 Watts/cm2.
When ignited, the exothermal reactive layer 312 may burn at a temperature
level of at least 1200 degrees Celsius to form a bonding joint (e.g., a
weld joint) between the interconnect member 290 and the cell terminal
354.

[0037] Referring to FIGS. 5 and 9, a system 500 for bonding the
interconnect members to cell terminals of battery cells of the battery
module 10 will now be described. Further, for purposes of simplicity, the
system 500 will be explained utilizing the interconnect member 90, the
exothermal reactive layer 112, and the battery cell terminal 154.
However, it should be understood that the system 500 can be utilized to
weld a plurality of other interconnect members to cell terminals in the
battery module 10 or in other battery modules. The system 500 includes a
clamping device 501, a component placement machine 502, a laser 504, a
mirror assembly 506, an optional electrostatic discharge device 507, and
a computer 508.

[0038] The clamping device 501 is configured to clamp the interconnect
member 90, the exothermal reactive layer 112, and the cell terminal 154
together, in response to a control signal from the computer 508. The
clamping device 501 clamps the interconnect member 90, the exothermal
reactive layer 112, and the cell terminal 154 together when the
exothermal reactive layer 112 is ignited to form the bonding joint. In
one exemplary embodiment, the clamping device 501 has clamping members
580, 581 and an actuator that moves the members 580, 581 toward one
another to apply a clamping force of 40-60 psi to the combination of the
interconnect member 90, the exothermal reactive layer 112, and the cell
terminal 154 disposed between the clamping members 580, 581, in response
to a control signal from the computer 508. After the bonding joint is
formed, the actuator moves the clamping members 580, 581 away from one
another to release the combination of the interconnect member 90, the
exothermal reactive layer 112, and the cell terminal 154, in response to
another control signal from the computer 508.

[0039] In the illustrated embodiment, the component placement machine 502
is configured to dispose the exothermal reactive layer 112 between the
interconnect member 90 and the cell terminal 154. In an alternative
embodiment, the component placement machine 502 is configured to dispose
an interconnect member having an exothermal reactive layer previously
disposed thereon adjacent to a cell terminal of the battery cell. In
still another alternative embodiment, the component placement machine 502
is configured to dispose an interconnect member adjacent to a cell
terminal of a battery cell having an exothermal reactive layer previously
disposed thereon. The component placement machine 502 is operably coupled
to the computer 508 and performs tasks based on control signals received
from the computer 508. In one exemplary embodiment, the component
placement machine 502 is a robotic placement machine.

[0040] The laser 504 is configured to iteratively emit a laser beam for a
predetermined amount of time in response to control signals from the
computer 508. In the illustrated embodiment, the laser 504 emits a laser
beam toward the mirror assembly 506 for less than or equal to 0.1
milliseconds. In an alternative embodiment, the laser 504 can be a
yttrium aluminum garnet (YAG) laser, a CO2 laser, a fiber laser, or
a disc laser for example.

[0041] The mirror assembly 506 is configured to receive a laser beam from
the laser 504 and to direct the laser beam toward a portion of an
exothermal reactive layer. In particular, the mirror assembly 506 directs
laser beams to predetermined locations based on control signals from the
computer 508. As shown, the mirror assembly 506 directs the laser beam
509 toward the exothermal reactive layer 112 to ignite the layer 112 for
forming a bonding joint 700 between the interconnect member 90 and the
cell terminal 154. The laser beam 509 has a power density of
0.1×108 Watts/cm2 to 5.0×108 Watts/cm2 at
the exothermal reactive layer 112. Further, the mirror assembly 506 can
direct a second laser beam 511 towards another exothermal reactive layer
to ignite the exothermal reactive layer 112. In one exemplary embodiment,
the mirror assembly 506 is a galvanic mirror assembly. In an alternative
embodiment, the mirror assembly 506 is a scanning mirror assembly.

[0042] The electrostatic discharge device 507 may be optionally utilized
instead of the laser 504 and the mirror assembly 506 to ignite the
exothermal reactive layer 112. In particular, the electrostatic discharge
device 507 emits an electrical spark or discharge in response to a
control signal from the computer 508 to ignite the exothermal reactive
layer 112.

[0043] Referring to FIGS. 9 and 10, a flowchart of a method for bonding a
cell terminal of the battery to an interconnect member in accordance with
another exemplary embodiment will be explained. It should be understood
that the following method can be iteratively performed to bond a
plurality of cell terminals to associated interconnect members. During
the explanation of the following method, it is assumed that the
exothermal reactive layer 112 is a separate distinct component.

[0044] At step 600, the component placement machine 502 disposes the
exothermal reactive layer 112 between the interconnect member 90 and the
cell terminal 154 of the battery cell 24, in response to receiving
control signals from the computer 508.

[0045] At step 601, the clamping device 501 clamps the interconnect member
90, the exothermal reactive layer 112, and the cell terminal 154 together
in response to a control signal from the computer 508.

[0046] At step 602, the laser 504 emits a laser beam 509 for a
predetermined amount of time in response to receiving a control signal
from the computer 508.

[0047] At step 604, the mirror assembly 506 receives the laser beam 509
from the laser 504 and reflects the laser beam 509 such that the laser
beam 509 contacts at least a portion of the exothermal reactive layer 112
and ignites the exothermal reactive layer 112 to form a bonding joint
700, shown in FIG. 13, between the interconnect member 90 and the cell
terminal 154. The mirror assembly 506 reflects the laser beam 509 toward
the portion of the exothermal reactive layer 112 in response to receiving
a control signal from the computer 508.

[0048] Referring to FIGS. 9 and 11, a flowchart of a method for bonding a
cell terminal of the battery to an interconnect member in accordance with
another exemplary embodiment will be explained. It should be understood
that the following method can be iteratively performed to bond a
plurality of cell terminals to associated interconnect members. During
the explanation of the following method, it is assumed that the
exothermal reactive layer 112 is previously formed on an outer surface of
the interconnect member 90 utilizing a vapor deposition method or a
magnetron sputtering method for example.

[0049] At step 640, the component placement machine 502 disposes the
interconnect member 90 having the exothermal reactive layer 112
previously disposed thereon adjacent to the cell terminal 154 of the
battery cell 24, in response to receiving control signals from the
computer 508, such that the exothermal reactive layer 112 is disposed
between the interconnect member 90 and the cell terminal 154.

[0050] At step 641, the clamping device 501 clamps the interconnect member
90, the exothermal reactive layer 112, and the cell terminal 154 together
in response to a control signal from the computer 508.

[0051] At step 642, the laser 504 emits the laser beam 509 for a
predetermined amount of time in response to control signal from the
computer 508.

[0052] At step 644, the mirror assembly 506 receives the laser beam 509
from the laser 504 and reflects the laser beam 509 such that the laser
beam 509 contacts at least a portion of the exothermal reactive layer 112
in response to receiving a control signal from the computer 508, and
ignites the exothermal reactive layer 112 to form a bonding joint between
the interconnect member 90 and the cell terminal 154.

[0053] Referring to FIGS. 9 and 12, a flowchart of a method for bonding a
cell terminal of the battery to an interconnect member in accordance with
another exemplary embodiment will be explained. It should be understood
that the following method can be iteratively performed to bond a
plurality of cell terminals to associated interconnect members. During
the explanation of the following method, it is assumed that the
exothermal reactive layer 112 is previously formed on a surface of the
cell tab 112 utilizing a vapor deposition method or a magnetron
sputtering method for example.

[0054] At step 680, the component placement machine 502 disposes the
interconnect member 90 adjacent to the cell terminal 154 of the battery
cell 24 having the exothermal reactive layer 112 previously disposed
thereon, in response to receiving control signals from the computer 508,
such that the exothermal reactive layer 112 is disposed between the
interconnect member 90 and the cell terminal 154.

[0055] At step 681, the clamping device 501 clamps the interconnect member
90, the exothermal reactive layer 112, and the cell terminal 154 together
in response to a control signal from the computer 508.

[0056] At step 682, the laser 504 emits a laser beam 509 for a
predetermined amount of time in response to receiving a control signal
from the computer 508.

[0057] At step 684, the mirror assembly 506 receives the laser beam 509
from the laser 504 and reflects the laser beam 509 such that the laser
beam 509 contacts at least a portion of the exothermal reactive layer 112
in response to receiving a control signal from the computer 508, and
ignites the exothermal reactive layer 112 to form a bonding joint between
the interconnect member 90 and the cell terminal 112.

[0058] The battery module 10 and the methods disclosed herein provide
substantial advantages over other methods. In particular, the battery
module 10 and methods provide a technical effect of utilizing exothermal
reactive layers that are ignited utilizing a laser beam during
manufacture of the module 10 to bond cell terminals of the battery cells
to interconnect members extremely quickly (e.g., less than 0.5 seconds).

[0059] While the invention has been described in detail in connection with
only a limited number of embodiments, it should be readily understood
that the invention is not limited to such disclosed embodiments. Rather,
the invention can be modified to incorporate any number of variations,
alterations, substitutions or equivalent arrangements not heretofore
described, but which are commensurate with the spirit and scope of the
invention. Additionally, while various embodiments of the invention have
been described, it is to be understood that aspects of the invention may
include only some of the described embodiments. Accordingly, the
invention is not to be seen as limited by the foregoing description.